Immanibelua sicuterrae, Vast Worldbeast

Domain: Eukaryota

Kingdom: Animalia

Phylum: Ctenophora

Class: Scleroctenophora

Order: Caelitera

Family: Orbitavora

Genus: Immanibellua

Species: I. sicuterrae

Length: 1 000 - 10 000 km

Phenotype Mass: 2*10²⁴ kg

Maximum acceleration: 10 m/s²

Sunplate surface area: 25 million - 500 million km²

Generation time: 500 thousand - 2 million years

Resonance: Contrabass

Conservation status: Vulnerable

The vast worldbeast (Immanibelua sicuterrae) is one of the largest animals of the reef as reconed by mass or total metabolism. They dwell around the sparse stars in the periphery of the reef where large bodies of solid matter are rare. It's easily recognized by its size, always moving in a narrow range of accelerations between 9 and 10 meters per second squared, and the distinct flat and round Sundisk exactly horizontal to its acceleration.

The vast majority of its time is spent circling its parent star at a full burn directly towards it and at 90 degrees to its velocity, keeping it's speed and the distance to the star constant in order to feed on the shell of plankton surrounding it. It's stomach is unusual, facing outward covering the majority of its surface but covered in tens of meters of mucus as well as a thick protective skin, and avoids starving by relying on it's speed colliding with food items at many kilometers per second letting them punch through the skin and embed themselves in the mucus or stomach tissue. It can acquire some nutrients and energy by interfacing with symbiotic plants on the Sundisk, but this gives orders of magnitude less than is needed to sustain acceleration.

The Vast Worldbeast is often considered a living fossil, and has changed very little in over 350 million years due to it's extremely long generation time and secluded habitat. The most notable of those differences is a quadrupling in size, and the acquisition of the symbiotic species Anthropo aeternalis that protects it from parasites and predator that arose after the Sophogen Mass Extinction 300 million years ago.

Every 40 000 years, Vast Wordbeast from hundreds of lightyears around will gather towards a single star to spawn. It is believed this is coordinated millenia in advance, by each individual studying the stars for signs of one about to enter a particular stage of its life cycle and that has a suitable environment around it for their spawn to survive once hatched. The journey takes many centuries during which they leave their orbits and travel through the interstellar darkness. The gathering of millions of these world-sized creatures, each laying hundreds of millions of eggs that in turn are eight kilometers across, is a truly spectacular sight, but often apocalyptic to the civilizations caught within it.

Before humans evolved, Worldbeast were frequent victims of poacher civilizations and flesh mining ports, but today this typically only happens if those very guardians turn against them, or are defeated in a full scale war.